Gas-cap.



UNITED s'ras ns P -mans: OFFICE.

I RICHARD FLEMING, OF LYNN, MASS ACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, ACORPORATION OF NEW YORK. 1

GAS-CAP.

Application filed May 4,

Specification oflietters Patent.

Patented Jan, 21,190

1905. Serial No- 258-796- T all whom it may concern:

"Be it known that I, RICHARD FLEMING, a

- citizen of the United States, residing at Lynn, ,county of Essex, and State of Massachusetts,

have inventedcertain new and useful Improvements in Gas-Caps, of which the'follow -is a specification.

. his invention relates to gas caps for inclosed arcQla-nips and its object is to provide irifcap'so constructed as-to give along carbon e. It has been found that inorder to get a long carbon life in opxerating inclosed arc lamps, the

r as the carbon is moved up and down bythe regulating mechanism its pumping action \Vllltransfer the inert carbon gases between the arc-inclosure and this passage and not drawoxygen freely into the arc-inclosure since oxygen hastens the consumption of the car bons. Some oxygen should be allowed to pass into the inclosurc as restricting the sup ly too much results in a graphitizption of t ie carbon tips diminishing film-{lanai the 5 arc and increasing its resistance, as under these conditions the carbon tips are less volatile. After considerable experimental work I have succeeded in producing a gas cap arranged to cover the open end of an arc-inclosing globe and having a passage theretlirough forming a receptacle or reservoir for the arc. gases'of such size and length that just theproper amount ofoxygen is supplied to the arc. This passage becomes filler w1th inert carbon oxids very shortly after the lamp is arc-inclosure or force it from turned on and the pumping action of the carbon as it is moved u and down by the regulating mechanism an the varying heat of the arc draw, the gas from the passage into the the inclosure into the passage; at the same time the passage permits the entrance of a limited amount of oxy en just sufficient to insure the operation oi the lamp under the best conditions.

I make this passage through the gas cap' in the form of a double spiral communicating with the arc-inclosure at one end and with the atmosphere at the other. Preferably the end of the passage communicating with. the atmosphere is an opening surrounding the cari on so that the hot gases passing through this openmgto the atmosphere will assist in the arc, s

The novel-features of my invention will be definitely indicated in the claims appended hereto. I 1

The details of constructionof my im roved gas cap will-be better understood byre erence to the following description taken in connection with the accompanyingv drawings which show the preferred embodiment of my invention and 111 which i lower portion o fan arc lamp with the outer 'globe removed; Fig. 2 ,is an enlarged section .of the gas cap; Fig. 3 is a plan v ew of the upper plate ofthe cap; Fi 4 a plan of the separating diaphragm; and the lower plate.

' Referring to the drawings, my improved together but separate by a diaphragm 3. The upper plate -1 has two posts 4 formed integral therewith by which the gas cap, is secured to the platform 5 which'ior ms-the bot-tom of the casing for the regulatii mechanism of the lam A bail 6 suspcnddii from the lat-form'5 hy springs incloscd in casings 7 iolds the arc-inclosing globe S in position with its open end pressed firmly against an accurately finished'surface' on the bottom of plate 2- so that air cannot enter between the globe and plate. The two plates, land 2 have 0 enings theret-hrough for the upper movable e ect'rode9. The opening through the lower plate 2 is accurately finished, is only very sli htly larger than the carbon 9 and is provided with upwardly and downwardly extending flanges formmg a tube, so that the passage of air or gas through this opening around'the carbon is prevented as much as. possible. In the lower plate 2 is an opening'lO and a spirally-arranged wall 11 forms a spiral groove in the plate beginning close to the opening 10. The 1&- phragm 3 is secured on top of the plate 2 making the groove a spiral assa eway and an opening 12 is provided t roug h the di phragm 3 in such ac parts are assembled t s opening 18 near the end of the spiral passageway. The upper plate 1 is provided with a spirally-arranged wall 13 forming a spiral roove and when laced down upon the 'aphragm 3 the atter makes this groove alsoa sp ral paslimiting the amount of oxygen admitted to Figure l. is'a sectional elevation oflthegas cap consi'sts'ot twolates l and 2 secured gigsition that when the '5 a plan of ing-12 in the diaphragm 3 and ends-at the center of the plate 1 where an opening is provided throu h the plate somewhat larger than the car on 9 so as to permit the gases to flow out of thep'assage comparatively freely around the carbon 9.

The plates 1 and'2 and the diaphragm 3 are secured together by screws 14. An opening is rovided'through the plates 1 munic'ating with the gas passage, to receive I and 2 and the diaphragm 3, but not com- -an insulating bushing 15 through which arod,-16 extends. At its lower end this rod 16 carries the holder 17 for the lower carbon '18 and at its upper end is secured a binding post .19, for connecting the lead from the negative binding vpost of the lamp.

It will be seen that when the plates 1 and 2 and diaphragm 3' are assembled and held tightly together by thescrews 14;, a passage in the form of a double spiral is at the other; When the lamp is turned on the gas from the are soonfilis'the globe 8 and the passage through the cap; then as the carbon 9 is moved up and down by the regulating mechanism its pumping action does not draw air into the arc-inclosure but merely draws inert carbon gas from the. passage into the globe or forces gas from the globe into the passagel The hot gases issuing om the passage to the atmosphere rise around the carbon 9 and assist in preventing the entrance of air intothe passage and directly into the arc-inclosure-around the car-'- bon. The length and capacity of the gas passage is such that some air does enter the arcinelosure through the gas passage but this is only enough to insure proper working .of the lamp. In former types of gas check for are lamps the air entered through a tubular duct of uniform diameter and short an op cnin IOVlded through the" gas cap "communicating-2.1 1th the globe 8 atone end and tlie'atnrosphere' other side of the plate; I

.arc inelosure.

eepted by a dead gas chamber into which is being forced-a laterally'moving stream of hot gas which acts as a check against direct indraft on the familiar principle.

lVhat I claim as new, and desire to secure by Letters Patent ot the UnitedStatcs, is

L'A gas cap for an inclos'ed are lamp having a doublyspiral passage therethrouglr for the are gases communicating-at one end'vrith the arcinelosure and at the other with the atmosphege. 2. gas canferfan nielosed arc plates, earl1 of said plates having an opening therethrough from the spiral groove to the- 3. A gas cap for an inelosed are lamp, comprising two plates, each having a spiral y extending open'channel formed in'one of its faces, a diaphragm closing the two channels laterally and connecting them longitudinally so as to form a continuous gas passag'e one amp comprr ltig' two plates each having a spiral groove there1n, and a diaphragm having threthrongh sep'aratmg the. two

of said channels having an opening to the 1 atmosphere and 4-. A gas cap for an inclosed arc lamp having a feed 0 ening for themovable eleetrode of larger 0 earanee' at the top than botthe other an opening to the tom, and a long tubular duct between the openings comnnn'ncatlng with the inner globe. i

In witness whereof; I have hereunto set my hand this twenty-eighth dayof April;

' RICHARD FLEMING.

Witnesses: v

JOHN A; M'oMA Us, 'Jr.- HEN Y O. WEs'rENnARP. 

